The present invention relates to a method for manufacturing a circuit board with continuous circuit traces between opposite sides.
Additive processes for manufacturing circuit boards generally involve coating a surface of a substrate with photoresist and masking the areas corresponding to desired circuit traces. Where circuitry is desired on both surfaces, a mask is prepared for the opposite side.
In order to test certain types of equipment such as racks in telephone central office equipment, it would be desirable to have test equipment connected to a circuit board which could be inserted into card edge type connectors in successive racks. A substrate profiled with a slot to insure correct alignment by mating with a key in the connector, as well as shallow channels near the mating edge of the substrate to insure retention by resilient contacts in the connector, would be most desirable. The prior art does not teach a method for forming traces on both sides of a substrate while forming continuous traces around the edge of a board so profiled.